1. Field of the Invention
This invention is directed to a system for sealing the chink between logs in a log structure. It is more specifically directed to a flexible sealant strip and the composition for making the strip for use in sealing the space between adjacent logs in a log structure.
2. Discussion of the Background
The southeastern part of the United States was colonized many years before the northwestern part of the country. The climate was much milder in the southeast and our forefathers had time to try to maximize their techniques of log home building. One of the things that they learned was that the center or heartwood of the log was dryer and more bug resistant than the outer sapwood layers. In order to reap these advantages, they hewed large slabs from the logs which were often 8″×14″ in size. These slabs were hewn from the center of the log. Double dovetailed joints were formed on the ends of the logs and the logs were stacked one on top of the other to form a wall for a log structure. This type of construction resulted in a southeastern regional style that has since become known as the Appalachian or Hearthstone Style.
Conversely, the climate in northwestern United States was much harsher and the early settlers were more interested in just getting the logs set in place so that they could have protection from the elements and the resulting style became the hand hewn, round on round style log structure.
Both styles normally had significant gaps or chinks between the logs and required some sort of chink filler to seal out the weather. The early chinking materials were normally clay, mud and straw or whatever was readily available. As log home structure development progressed, the chinking materials improved with the use of concrete, tar and even wooden wedges and splines. All of these chinking advances failed because the builders were still trying to seal a dynamic or continuously moving joint with a solid or non-flexible chinking material.
This problem became so well recognized by the log structure industry that by 1980 close to seventy percent (70%) of the log home companies in the United States and Canada were marketing various chinkless style homes. The chinkless style structure was created either by attempting to copy some of the old world scribe fit techniques or by trying to machine log mating surfaces with some sort of tongue and groove or spline joint that would keep out the elements. These attempts, though heavily marketed, were generally failures and by the 1980's various companies were attempting to develop an elastomeric chinking material to take its place. Most of the industry was still focusing on attempting to use concrete as the base material and achieve the desired elastic characteristics through the addition of various polymers. These prior art methods and materials also were destined for failure.
In the early 1980's the applicant developed the first all elastomeric chinking material for use in filling and sealing the chink or gaps between the logs in this type of structure. Various types of foam backer rods having various cross-sectional shapes were also used in filling the chink prior to applying the chinking sealant material.
Other attempts to close and seal the chink found between the surfaces of adjacent logs included installing elastomeric or resilient blocks between the logs at the time of construction with the blocks being somewhat compressed to adequately fill the void. In addition to the blocks, elongated splines fabricated from thin sheet material were installed longitudinally along each side of the blocks, usually within slots provided in the lower surface of the upper log and the upper surface of the lower log. These splines were arranged to fit within these slots to hold them in position and the splines were then nailed to the bottom log to rigidly attach the splines in place. A chinking sealant material could then be applied to the outside surface of the splines both on the inside and outside of the log structure to provide a finished appearance. This same type of construction was used in both the round on round type structure as well as the hewed slab type log structure.
In addition to these variations for sealing the chink, the splines were formed from waterproof or water resistant materials with the top and bottom joints or edges of the splines sealed by caulking. As it has been found over the years, these types of chinking materials and sealants did not prove to be permanent or completely adequate.
Recently, attempts have been made to pre-apply chinking sealant materials to the outer surface of the individual splines and the splines which were provided in fixed lengths were then delivered to the job site for installation. The problem with this type of construction was that the vertical joints between the adjacent splines, had an abutting joint which was difficult to seal to prevent the introduction of water and air which accelerated the deterioration of the joint which proved to be quite unsatisfactory.
The present invention is directed to a new and novel method to eliminate the problems which have been encountered in the past in trying to seal the chink between logs in log structures. It is an object of this invention to provide a low cost semi-flexible strip or tape sealant which can be easily applied in order to permanently seal the joint and prevent the introduction of the elements or contaminants. Another object of the present invention is to provide a relatively inexpensive sealant arrangement which can be easily applied by unskilled workers, including the home owner himself. A still further object of the present invention is to provide a chinking closure system which can be readily applied in various weather and temperature extremes and which has a generally long shelf life which allows it to be viable for a considerable length of time without deterioration, both before use as well as after.
3. Information Disclosure Statement The following statement is provided to comply with the applicant's acknowledged duty to inform the Patent and Trademark Office of any pertinent information of which he is aware. The following information refers to the most pertinent patents of which the applicant has knowledge with respect to the subject matter of the present invention. There is no intent to show that a comprehensive patentability search has been performed on the subject.
The Boucquey, et al patent (U.S. Pat. No. 4,185,428) discloses a device for sealing juxtaposed parallel logs separated by spacers. The spacers are intended to be narrower than the width of the log. The joint comprises a flat strip of resilient material having profiled flanges bent at about right angles with respect to the flat portion of the strip and adapted to be snapped in confronting longitudinal grooves made in the juxtaposed logs. An insulated sealing material is interposed between the strip and the spacer.
The Hauptman patent (U.S. Pat. No. 4,356,676) discloses a sealant strip which is provided having a soft, resilient synthetic foamed resin core. A pressure sensitive adhesive coating is applied on at least one of two of the opposed sides of the core and a thin, preferably silicone rubber sealing layer is cured in situ on the two remaining surfaces of the core. The strip is adapted for adhesive attachment to and compression between the log structural members with the core separating the edges of the sealing layers in contact with the opposed surfaces of the log structural elements. The strip is permanently positioned between the surface of the logs in order to seal the surfaces between the log structural members.
The Giles, et al patent (U.S. Pat. No. 4,918,888) discloses a chinking closure system comprising a compressible block which is inserted into a chink defined between adjacent log structural members. The block has a longitudinal axis which is substantially parallel with the longitudinal axis of each of the logs defining the chink. Elongated relatively rigid thin sheet splines are provided on each side of the block member and are inserted in grooves formed along the outer edges of the log structural members. These closure members or splines can be pre-coated with a textured finish to resemble mortar or the surfaces can be coated at the site. The closure members or splines can also be fabricated on a thin backing material and rolled for shipment to the construction site.
The Giles patent (U.S. Pat. No. 5,505,028) discloses the southeast style of log construction wherein the logs are formed by cutting longitudinal grooves in the upper and lower surfaces of the hewed logs with a corresponding spacer block disposed between the logs within the structure. In this way, the chink is filled by the spacer block to seal the void between the logs during the construction.
The Sharp patent (U.S. Pat. No. 5,787,661) discloses a simulated log structure providing a corner type assembly. The corners are positioned at the edges of the structure while a standard frame structure for the walls is provided. Simulated log strips or siding are positioned along the wall structure with simulated mortar strips provided between the siding sections. The mortar simulates the chinking material of a normal log structure. Vinyl siding can be used to simulate the logs themselves and mortar or gray tape can be provided between the siding strips to represent the chinking material.
The Davidson patent (U.S. Pat. No. 6,000,177) shows a simulated log structure similar to the Sharp patent wherein wood framing construction is used with a plurality of interlinking log ends forming the corner of the structure. Wall boards are attached horizontally to the construction frame and wood strips covered with a suitable surface material, such as paint, stucco or mesh material to simulate conventional chinking material are described.
The Foster patent (U.S. Pat. No. 4,822,655) shows a preformed sealant tape formed from butyl rubber which is essentially formed in three layers. The top layer is an abrasion resistant rubber membrane with a release paper forming the lower layer. Plasticized butyl rubber is positioned there between. The tape is unrolled as the release paper is removed. The butyl rubber has substantial adhesion and can be pressed into a joint to conform to the joint and to seal the joint against the introduction of moisture or other contaminants. This tape simulates liquid caulk for sealing openings or joints. There is no simulated masonry or chinking material pre-coating the tape to simulate conventional chinking materials.